Answer:
Since with 15 apples we are able to make 3 pies, this means that in each pie there are 5 apples (15apples divided by 3 pies = 5 apples.)
If there are 12 pies we simply have to multiply 12x5 which equals 60, this means that if we needed to make 12 pies we would need 60 apples.
15apples:3pies = 60apples:12pies